openwrt/target/linux/bcm27xx/patches-5.15/950-0631-drm-vc4-hdmi-Move-clock-calculation-into-its-own-fun.patch

From 60b7ddb0b3c9d906a20d8a84e527ccf5a792a64b Mon Sep 17 00:00:00 2001
From: Maxime Ripard <[email protected]>
Date: Thu, 2 Dec 2021 17:04:18 +0100
Subject: [PATCH] drm/vc4: hdmi: Move clock calculation into its own
 function

The code to compute our clock rate for a given setup will be called in
multiple places in the next patches, so let's create a separate function
for it.

Signed-off-by: Maxime Ripard <[email protected]>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 49 +++++++++++++++++++++++-----------
 1 file changed, 34 insertions(+), 15 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1265,6 +1265,35 @@ vc4_hdmi_encoder_clock_valid(const struc
 	return MODE_OK;
 }
 
+static unsigned long long
+vc4_hdmi_encoder_compute_mode_clock(const struct drm_display_mode *mode,
+				    unsigned int bpc)
+{
+	unsigned long long clock = mode->crtc_clock * 1000;
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		clock = clock * 2;
+
+	return clock * bpc / 8;
+}
+
+static int
+vc4_hdmi_encoder_compute_clock(const struct vc4_hdmi *vc4_hdmi,
+			       struct vc4_hdmi_connector_state *vc4_state,
+			       const struct drm_display_mode *mode,
+			       unsigned int bpc)
+{
+	unsigned long long clock;
+
+	clock = vc4_hdmi_encoder_compute_mode_clock(mode, bpc);
+	if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, clock) != MODE_OK)
+		return -EINVAL;
+
+	vc4_state->pixel_rate = clock;
+
+	return 0;
+}
+
 #define WIFI_2_4GHz_CH1_MIN_FREQ	2400000000ULL
 #define WIFI_2_4GHz_CH1_MAX_FREQ	2422000000ULL
 
@@ -1277,6 +1306,7 @@ static int vc4_hdmi_encoder_atomic_check
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 	unsigned long long pixel_rate = mode->clock * 1000;
 	unsigned long long tmds_rate;
+	int ret;
 
 	if (vc4_hdmi->variant->unsupported_odd_h_timings &&
 	    !(mode->flags & DRM_MODE_FLAG_DBLCLK) &&
@@ -1298,21 +1328,10 @@ static int vc4_hdmi_encoder_atomic_check
 		pixel_rate = mode->clock * 1000;
 	}
 
-	if (conn_state->max_bpc == 12) {
-		pixel_rate = pixel_rate * 150;
-		do_div(pixel_rate, 100);
-	} else if (conn_state->max_bpc == 10) {
-		pixel_rate = pixel_rate * 125;
-		do_div(pixel_rate, 100);
-	}
-
-	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
-		pixel_rate = pixel_rate * 2;
-
-	if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, pixel_rate) != MODE_OK)
-		return -EINVAL;
-
-	vc4_state->pixel_rate = pixel_rate;
+	ret = vc4_hdmi_encoder_compute_clock(vc4_hdmi, vc4_state, mode,
+					     conn_state->max_bpc);
+	if (ret)
+		return ret;
 
 	return 0;
 }